Answer: She should use 12 ounces of Sweet Rose Tulsi tea and 4 ounces of Orange blossom green tea.
Explanation:
Let x represent the number of ounces of Sweet Rose Tulsi tea that she should use.
Let y represent the number of ounces of Orange blossom green tea that she should use.
She wants to blend 16 ounces of the tea blend. It means that
x + y = 16
x = 16 - y
Sweet rose tea sells for $4.98 an ounce and Orange Blossom sells for $1.98 an ounce. If the the tea blend is to sell for $4.23 per ounce, then the 16 ounces would be sold for 16 × 4.23 = 67.68
it means that
4.98x + 1.98y = 67.68- - - - - - - - - - -1
Substituting x = 16 - y into equation 1, it becomes
4.98(16 - y) + 1.98y = 67.68
79.68 - 4.98y + 1.98y = 67.68
- 4.98y + 1.98y = 67.68 - 79.68
- 3y = - 12
y = - 12/-3
y = 4
x = 16 - y = 16 - 4
x = 12